Hard disk devices have hitherto been used in apparatuses for information processing such as computers. In recent years, the hard disk devices have been loaded not only as external storage devices for computers but also in home appliances such as television devices and video devices and electronic devices for automobiles.
In a conventional hard disk device 200 illustrated in FIG. 20, a drive mechanism is housed in a casing body 201. The drive mechanism includes a spindle 203 that rotationally drives a hard disk 202 which is a recording medium (the spindle 203 being rotated by a motor not illustrated), a carriage 205 that supports a magnetic head 204 for recording information on the hard disk 202 and reading out recorded information from the hard disk 202 and rotates on a plane of the hard disk 202, a VCM (voice coil motor) 206 that precisely rotates the carriage 205 to regulate scanning of the magnetic head 204, and a pivot shaft 207 that is fixed to the casing body 201 and connects the casing body 201 to the carriage 205. The pivot shaft 207 is, for example, in a substantially columnar form and has a construction of a bearing.
The carriage 205 rotates on a plane of the hard disk 202 with the pivot shaft 207 serving as a central axis. In this case, a tolerance ring is used for fixation between the carriage 205 and the pivot shaft 207. The fixation of the carriage 205 to the pivot shaft 207 prevents power, involved in the rotation of the carriage 205 by the VCM 206, from being conveyed to the casing body 201.
The tolerance ring is a ring that is formed of a flat member rolled along a predetermined direction to a substantially circular form. The tolerance ring is inserted into an opening on the carriage 205 side, and the pivot shaft 207 is then pressed into the tolerance ring. For this type of tolerance ring, a tolerance ring is disclosed that has a plurality of protrusion-shaped contacting parts protruded on the outer circumferential side (see, for example, Patent Literatures 1 to 4). In tolerance rings described in Patent Literatures 1 to 4, contacting parts are brought into pressure contact with the side surface of either the carriage 205 or the pivot shaft 207 for fixation between the carriage 205 and the pivot shaft 207.